UPDATE: The Kilogram Redefined
As was mentioned in our October 20th top science news blog, the General Conference on Weights and Measures in Versailles, France has decided to redefine the kilogram, along with the ampere, the kelvin and the mole.
For more than 130 years the International Prototype Kilogram (IPK), a cylinder of a platinum alloy stored at the International Bureau of Weights and Measures (BIPM) in France, has been used to define the kilogram. Several close replicas of the IPK have been made and distributed around the globe, however, discrepancies have been found between the IPK and its replicas as they have deteriorated over time. Although the discrepancies are minute, this has a big impact when scientists are measuring at a tiny scale, therefore a more robust solution is necessary to ensure the stability and accuracy of this measurement over the longer term.
Planck’s constant, which enables weight to be related to electrical current will be used to measure the kilogram. This is done because electromagnets generate a force, this force is directly proportional to the amount of electrical current going through its coils, therefore, there is a direct relationship between this force and electricity (Planck’s constant).
To measure Planck’s constant, and therefore the kilogram, the Kibble Balance, a set of super-accurate scales developed by Dr Bryan Kibble, will be used. The Kibble Balance has an electromagnet that pulls down on one side of the scales, while a weight, in this instance a kilogram, is placed on the other side. The electrical current going through the electromagnet is then increased until the two sides are balanced, giving an incredibly accurate calculation of Planck’s constant.
Using the IPK meant that every few decades the replica kilograms had to be measured against the original. With the new method, coming into force on 20th May 2019, anyone with a Kibble Balance will be able to check their weights any time.
An InSight into Mars
NASA has reached another milestone with its InSight spacecraft blazing through the Martian atmosphere and landing safely on the surface of the Red Planet on Monday 26th November. The lander touched down near Mars’ equator on the western side of a flat, smooth expanse of lava called Elysium Planitia. The team leading InSight’s entry, descent and landing, based at NASA’s Jet Propulsion Laboratory in Pasadena, California, and at Lockheed Martin Space in Denver, had pre-programmed the spacecraft to perform a specific sequence of actions to make this possible.
Only about 40% of missions sent to Mars globally have been successful. This is because of the extreme conditions found on Mars, including an atmosphere of only 1% of Earth’s, meaning there is very little friction to slow down the spacecraft. A parachute and retrorockets were used to decelerate the spacecraft. InSight hit the Martian atmosphere at 12,300 mph (19,800 kmph), and the whole sequence until touching down on the surface took only six and a half minutes.
InSight’s two-year mission will be used to study the deep interior of Mars so that we can learn how rocky planets, including Earth and the Moon, formed and how they could have developed so differently from one another.
Potential Peanut Allergy Treatment
A severe food allergy of any kind is life-altering, not only for the sufferer but also for their families, with the best practice being total avoidance. However, this isn’t always an easy option. Research sponsored by Aimmune Therapeutics and published in the New England Journal of Medicine has shown some advancement in the potential treatment of peanut allergy.
The trial involved nearly 500 children with a severe peanut allergy and successfully desensitised two-thirds of those who completed the trial. The study involved gradually increasing a tiny dose of peanut protein over a period of six months. After one year of treatment, the children could eat the equivalent of three to four peanuts.
However, several adverse effect were uncovered during the research with patients suffering from high rates of allergic reactions including hives and stomach pains as the dosage of peanut protein was increased. Furthermore, over 20% of the patients dropped out of the trial. The potential cost of the treatment may end up outweighing the benefits as patients would have to keep taking the medication to maintain tolerance levels, possibly for life.
Written by Jeanne Kroeger